UPSC'S MAIN JOB IS TO SELECT ELIGIBLE CANDIDATES FOR IAS....FIRST...

• UPSC selects candidates for IAS...first....and selection for other services such as IPS, IFS, IRS etc is incidental.
• The main focus of the Interview Board, hence, is to test the suitability of candidates for IAS only.....
• If so, the order of preferences given by a candidate in the Mains application is very important factor. If a candidate gives IAS as his/her first choice, for the Board, it is a common factor. If the candidate's first preferences is not IAS, but say, IFS or IPS is his/her first choice, then the Borad becomes "curious" about his/her choice of preference, as the Board has now to test the suitability of the candidate for IFS or IPS...which becoms interesting.
• The candidate prefers IFSor IPS to IAS has to prepare well to convince the Board about his choice. The answes must be true to his/her personality with solid reasoning behind it. Why do you want to be an IFS officer or IPS officer? Why did you not choose IAS ?
• The order of preferences by a candidate is an important area for the Board to draw its attention. Be prepared.